(1) Field of the Invention
The present invention relates to tools, pulling implements, and metal working apparatus having axially shiftable puller elements; and, particularly, relates to such devices including a bar forming a work extractor engaging a strap or wire for tensioning and to such devices including screw apparatus.
(2) Description of the Related Art
The present invention is particularly adapted to removal of a lock wire which retains a generally circular head within an open end of a generally cylindrical can forming, with the head, a case of a conventional gas generator. The drawings show a representative such case with its can, head, and lockwire identified by respective numerals 10-12. The lock wire has a hole 13 which is utilized with the present invention. The gas generator is not, in other respects, directly related to the present invention.
However, as further background of the invention, it is explained that the case contains a quantity of combustible material which is ignited to generate hot cases which exit the case through a nozzle, not shown. When it is desired to dispose of unused such gas generators, it is necessary to open their cases and remove the combustible material.
However, it has been found that this is extremely difficult due to the relative inaccessibility of the lock wire after assembly of the case and due to corrosion of the case elements at the lock wire. Disposal of the gas generator by burning or opening the case by cutting into it are dangerous, so that, despite the difficulties involved, it has been attempted to withdraw the lock wire by engaging it with a clamp motivated by a slide hammer. However, this method is often unsuccessful and, in any event, is tedious and likely to result in injury.
In gas generator cases to which the present invention is particularly adapted, such head 11 is received within the can 10, the can having an internal cylindrical surface 20 and the head having an external surface 21 conforming to surface 20 and engaged therewith. Surfaces 20 and 21 have respective circumferential grooves 22 and 23 of rectangular cross section which are axially aligned so as to receive the lock wire 12. The wire has a cross section conforming closely to the groves and thus engages both the can and head so as to retain the head axially within the can. As will be explained in greater detail, the lock wire is installed through an opening 25 in the can which extends tangentially into grooves 22 and 23. An end of the lock wire extends from the grooves into opening 25 and bears a hole 13, this lock wire end being disposed so that the hole is barely accessible from the exterior of the can when the wire is installed therein.
A tool embodying the principles of the present invention is constructed to pull a wire or the like, which corresponds to lockwire 12, from within a structure such as a gas generator case where the wire is, typically, disposed between mating cylindrical surfaces such as surfaces 20 and 21 from which the wire extends tangentially through case opening 25 in the case to a termination of the wire disposed at the exterior of the case. The tool has a body which mates, as subsequently described, at one side with conforming exterior elements of the case adjacent to an opening corresponding to opening 25. The tool body is constructed so that, when so mated to the case, the body extends tangentially of such mating cylindrical surfaces and from this one body side. The tool has an extraction rod extended through the body within a square passage therein extending from the case opening and extended tangentially of the mating, cylindrical surfaces when the body is so mated.
A wire corresponding to lockwire 12 is typically of rectangular cross section with opposite surfaces, which are parallel to the axis of the cylindrical mating case surfaces, and with a cylindrical hole corresponding to hole 13 disposed in the lockwire termination so that this hole extends between these opposite lockwire surfaces.
The extraction rod portion adjacent to the case is of square cross section and is slidably fitted to the body passage through which the rod extends. This rod portion has a wire engaging end which is juxtapositionable to the case opening and lockwire hole and which has a pair of jaws disposed to fit oppositely over the before-mentioned lockwire termination surfaces so that a bore in each jaw is aligned with the hole. An opening in the tool body is disposed above the rod end and provides for the insertion of an extraction pin through this opening and then through the aligned jaw bores and lockwire hole, thereby connecting the rod and the lockwire.
The extraction rod end portion opposite the square portion of the rod is provided with male screw threads and extends outwardly of the body in a direction away from the wire engaging rod end when the jaws thereof are connected to the wire by the extraction pin. The tool is provided with a nut screw-threadably engaged with these rod threads outwardly of the body and oppositely of the case so that appropriate rotation of the nut urges the extraction rod away from the case so as to withdraw the wire with considerable force through an opening corresponding to opening 25 and in a direction tangentially from between the mating cylindrical surfaces within the case. This force is sufficient to withdraw the wire despite corrosion and other impediments to withdrawal of the wire.
It is an object of the present invention to provide a tool for extraction of a lockwire from between mating cylindrical elements such as a head and can of a gas generator case.
Another object is to provide such a tool generating sufficient force to so extract such a wire despite corrosion and other impediments to extraction.
Still another object is to provide such a tool which generates such force and yet is fitted to such a case and lockwire so that they are undamaged during extraction of the wire.
Yet another object is to provide such a tool having extraction elements configured to securely engage a lock wire termination which, when installed, is closely received and barely accessible within an opening of the case.
A further object is to provide such a tool which provides the above objects; which is easily portable, convenient and safe to use, and economical to construct; and which is fully effective.